The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 04, 2006
Filed:
Mar. 22, 2002
Nobuyoshi Uno, Futtsu, JP;
Hideo Kanisawa, Muroran, JP;
Nobuyoshi Uno, Futtsu, JP;
Hideo Kanisawa, Muroran, JP;
Nippon Steel Corporation, Tokyo, JP;
Abstract
A high strength bold superior in delayed fracture resistant property has a bolt tensile strength of 1200 N/mm. A high strength bolt comprised of a head portion and shaft portion formed by a steel material, wherein the relation between a bolt tensile strength TS (N/mm) and tempering temperature T (° C.) satisfies the following expression (1), the relation between the bolt tensile strength TS (N/mm) and the carbon equivalent C(%) calculated from the chemical composition of the steel material used for the high strength bolt satisfies the following expression (2), and the tensile strength of the bolt is refined to a range of 1200 N/mmto 1600 N/mmby quenching and tempering:≦1.1+850  (1)≦550+1000  (2)